Methods and devices for automatically controlling friction clutches are known. The friction clutch is disengaged and engaged by a clutch actuator, where an actuating element such as a disc spring or another lever element is axially displaced by the clutch actuator along an actuation path, thereby controlling a friction lock between the friction clutch and friction linings of a clutch disc. The actuating element is, for example, displaced by pre-controlling the actuating element by means of the clutch actuator to a setpoint that corresponds to a desired target torque transferable via the friction clutch and is converted by the clutch actuator into the corresponding actuation path. The target torque formed from data of the driver's desired torque and operating data from the internal combustion engine are converted into the setpoint and then, finally, into the actuation path by using a clutch characteristic. This supplies the relationship between the target torque and the setpoint as an adaptable friction coefficient and takes into account the short-term and long-term changes to the friction clutch such as the sampling point at which the friction clutch starts transmitting torque and the maximum transmissible torque when the friction clutch is engaged. After the actuation path is pre-controlled, it is regulated by comparing the target and actual setpoint using a read-in actual value by means of a so-called position regulator. The engaged friction clutch can be regulated such that it is not completely engaged. Instead, for example, the torque provided by the internal combustion engine is transmitted including, if applicable, a safety margin. A slight amount of friction clutch slip is permissible here in order, for example, to attenuate torque peaks in the internal combustion engine.
It has been revealed that undesirable states of adhesion of the friction clutch and increased internal combustion engine speed can occur, which can be compensated by the position regulator but which necessarily arise from miscalculations of the method for controlling the friction clutch.
Thus, there is a long-felt need to develop methods for automatically controlling friction clutches and devices therefor.